15 " tires vs 17" for ride comfort

A nail in any tire will result in a near flat regardless. Be it 15" or 17" unless you are in one of those crazy monster trucks with the big, thick tires. But then, you wouldn't be in a prius anymore.

I have a 2012 Prius v model V as well and it has the Toyo tires on it. I am experienced a howling or growling sound coming from the rear of the car. The dealer believes the problem to be the Toyo tires but expresses his inability to correct the problem because Toyota does not make the tires. They did permit me to drive another model just like mine and it has the same howling noise. The noise is always there but changes volume depending on the road surface. Very annoying - any experiences here? Thx, Chuck

It’s probably not the tires. The brake rotors get a light surface coating of rust in humid or rainy weather which cause the rotors to vibrate from the brake pads rubbing intermittently on the rusty surface. This causes a howling or growling noise as you described. Try stopping several times from speed using hard braking action. This will clear the rust from the brake rotor surface and the noise should go away until the rust comes back. See "2012 Prius V Groaning Noise" in the Prius V technical forum.

i have toyo proxes A20 17's i have not heard any groaning.

my prius v five w/toyo tires 34lbs front and rear, rides better than my 2009 venza, with even taking out up to five lbs of air pressure. the prius rides smooth at all speeds up to 75 mph at least 1/2 an hour. does anyone have toyo proxes on their v, and how do you like them ??

The ride is smooth in my v and I hear no growling. Ok, sometimes I hear growling, but it's pretty much always from dogs in the back.

I have the Toyo Proxes and have heard excessive road noise on a particular type of pavement. I'd watch and see when you hear it if it's very road surface type or specific ones. I hear it on (unknown term) pavement where gravel is put down and then a tar mixture spread over to seal it and what looks like cement (not asphalt) with lines cut into it. I can grab a photo of each if my verbal description isn't clear.

As for the tires I don't have any issues with them at current but have read they are prone to early sidewall failure which worries me. W

I too was disappointed in ride and noise w/ 17" wheels so swaped out OEM "w" (?!) rated tires for Michelin Serenity and now mostly pleased. Only got the five package for the radar cruise and very happy with that. I would have prefered 15" wheels for a better ride.

Speaking of noise ... how do you disable the "pedestrian warning speaker" ?